Sensitizers for photographic silver halide emulsions



United States Patent "ice 3,253,919 SENSITIZERS FOR PHOTOGRAPHIC SILVER HALIDE EMULSIONS Dorothy J. Beavers, Charles V. Wilson, and Charles F. H.

Allen, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed June 12, 1962, Ser. No. 201,788

11 Claims. (Cl. 96-50) This invention relates to photographic silver halide emulsions, and more particularly, to an improved means for sensitizing such photographic silver halide emulsions.

A number of methods have been previously described for increasing the sensitivity of photographic silver halide emulsions other than methods of optical or spectral sensitization which involve the incorporation of certain colored compounds or dyes in the emulsions. The incorporation of such dyes in the emulsions increases or extends the optical range of sensitivity and for this reason such dyes are commonly referred to as optical or spectral sensitizing dyes. It is also well known to increase the sensitivity of photographic emulsions by the addition of sulfur compounds capable of reacting with silver salts to form silver sulfide, or with reducing agents (compounds of these types are also naturally present in gelatin) or with salts of gold or other noble metals, or with combinations of two or more of the aforementioned compounds generally known as chemical sensitizers. Such chemical sensitizers are believed to react with the silver halide to form, on the surface of the silver halide minute amounts of silver sulfide or of silver or of other noble metals, and these processes are capable of increasing the sensitivity of developing-out emulsions by a very large factor. However, there is a definite limit 'beyond which further additions of chemical sensitizers or of further digestion with the sensitizer present, merely increases fog of the photographic emulsion with constant or decreasing emulsion speed.

We have now found a means of further increasing the sensitivity of photographic emulsions which may be applied even through the ordinary processes of chemical sensitization have been carried to the effective limit of the photographic emulsion in question. Our process is to be distinguished from hypersensitization which is produced by bathing a finished coating with water or with solutions of ammonia, amines or silver salts. Such processes act primarily on optically sensitized photographic emulsions and tend to increase the free silver ion concentra tion of the emulsion and greatly diminish its stability. Ourprocess is also to be distinguished from hypersensitization "by mercury vapor which gives a transistory effect that is lost on storage of the film. The compound-s used in our invention do not appear to be chemical sensitizers in the usual sense, since they increase speed by their presence during exposure and processing, and require no digestion with the photographic emulsions to produce an increase in speed nor does their chemistry indicate that they are likely to react with silver halide under normal emulsion conditions.

The novel sensitizers of our invention, the polyfunctional polyalkyleneglycol compounds and their polyquaternary ammonium salts which are derived from ethylenediamine tetraacetic acid, alkylaminopropylamine-N,N,N'- trisacetic acid, polyamino alcohols, N methylglu'conamine (or N-methyl-glucamine) and contain at least six alkyleneglycol units per molecule, are unique in that the effects produced are additive in photographic emulsions which have already been sensitized to their optimum or near optimum with conventional chemical sensitizers, such as labile sulfur compounds. The novel sensitizers of our invention, however, can be used to sensitize photographic silver halide emulsions containing no other sensitizers if Patented May 31, 1966 desired. The novel sensitizers of our invention are not strictly chemical sensitizers since chemical sensitizers do not generally provide the additive efiects of the type mentioned.

It is therefore an object of our invention to provide photographic emulsions that have been sensitized with our polyfunctional polyalkyleneglycol sensitizer compounds or polyquaternary ammonium salts derived from them.

It is a further object of our invention to increase the light sensitivityof ordinary photographic silver halide emulsions which have been sensitized with chemical sensitizers, such as compounds containing labile sulfur atoms or gold containing compounds without increases in fog which might seriously effect the usefulness of the emul- 510118.

A further object is to provide a novel class of sensitizers which are readily dissolved in water and added to gelatinosilver halide emulsions.

A still further object is to provide a novel class of sensitizers which when added to photographic silver halide emulsions, produce their sensitizing effects without further digestion of the emulsion.

Other objects will become apparent from the following specification and claims.

According to our invention the sensitivity of ordinary high speed silver halide emulsions chemically sensitized in the conventional way is substantially increased by the incorporation of our polyfunctional polyalkyleneglycol sensitizers or polyquaternary ammonium salts derived from them. Our novel sensitizers are particularly useful since they have a high degree of water solubility and are readily incorporated in the silver halide emulsions in sensitizing amounts.

Included in the compounds of our invention are those having the formula:

in which p represents an integer of from 2 to 10; Z represents in which R is an alkyl group having from 1 to 20 carbon atoms such as methyl, ethyl, butyl, octyl, decyl, dodecyl,

- pentadecyl, heptadecyl, octadecyl, phytyl, etc.,, and X is an acid anion, such as chloride, bromide, perchlorate, a lower alkylsulfonate, e.g., methylsulfonate, ethylsulfonate, propylsulfonate, butylsulfonate, etc., an arylsulfonate, e.g., p-tolu'enesulfonate, 'benzenesulfonate, etc.; A A and A each represents a polyalkylene oxide chain derivative of a short alkyl chain having from 2 to 3 carbon atoms and containing an -OH or a group in which the number of alkylene oxide units may be the same or difierent and in which the alkylene oxide units may have from 2 to 3 carbon atoms per unit, such as ethylene or propylene and such that when the alkylene oxide units have 3 carbon atoms, Z represents a EN R X group; and B represents an alkyl group having from 1 to 20 carbon atoms, such as methyl, ethyl, propyl, butyl, heptyl, octyl, decyl, dodecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, phytyl, etc., or may be the same as A1, A2 or A3. II CH3 CH3 CH3 Z-C H-C H2[(C H2) r]2% C 2115 C .(OCHzCHrM-OH in which Z is as defined previously, and n is an integer such that the average value of n is from 8 to III in which R represents an alkyl group having from 1 to 20 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl, octyl, dodecyl, pentadecyl, hexadecyl, phytyl, etc.; m is an integer from 2 to 3; q and q each represent an integer such that the total of the 4qs and q has an average value of from 6 to 100; Y represents a hydroxyl group, a

group or a group in which R R and R each represents an alkyl group having from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, butyl, etc., and X represents an acid anion as described previously, such that when m is the integer 3, Y represents a group or a R: .N:R3 X9 R4 group.

Included among our sensitizers of Formula I are those of Formulas IV, V, VI, and VII which follow.

n +n +n +n has an average value of from 6 to 100, and Z is as defined previously.

H20 2O)n in which n n n and 11 and Z are as defined previously,

in which 11;, n n;,, and n.; and Z are as defined previously, and

VII CH in which R represents an alkyl group having from 1 to 20 carbon atoms such as methyl, ethyl, propyl, butyl, heptyl,

.octyl, decyl, dodecyl, pentadecyl, heptadecyl, octadecyl,

nonadecyl, phytyl, etc.; n n and n each represent an integer such the sum of n +n +n has an average value of from 8 to 100; and P and X are as described previously..

I] care o orno Hau -011 4 Our sensitizers of Formula III include those of the fol lowing formula:

VIII CH 0 in which Y is as defined previously and n is an integer that can be the same or different from n n n and n such that the total of n +n +n +n +n has an average' value in the range from 6 to 100.

Included among the polyfunctional polyethyleneglycol (i.e., polyfunctional PEG) sensitizing compounds and their polyquaternary salts are the following representative examples used to illustrate but not limit our invention.

Sensitizer Sensitizer Name Number Ethylenediamine tetraaeetic aeid-tetrakis (nonaethyleneglycol ester) or polymeric product therefrom.

704 (Average of 16 ethylene oxide units per molecule). Tctrahydroxyethylethylenediamine polyethylene glycol 550 (Average of 12.5 ethylene oxide units per molecule). Tetrahydroxyethylenediamine polyethylene glycol 3916 (Average of 9 ethylene oxide units per molecule). Tetrahydroxyethylethylenediamine polyethylene glycol- 176-bis(methyl p-toluene-sullonate) Heptadecylaminopropylarnino-N,N ,N-trispolyethyleneglycol-1320-bls (methyl p-toluene-sulfonate) l-Dimethylamin0-3,6,9-trirnethyl-3,6,9-triazaundecanol-1- polyethyleneglycol 525 (Average of 12.1 ethylene oxide groups per molecule). l-Dlrnethylamino-3,6,9-trimethyl-3,6,9-trlazaundecanol-lpolyethyleneglycol 977 (Average of 22.2 ethylene oxide units per molecule). 1-Trimethylammonium-3,6,9-triaza-3,3,6,6,9,9-hexarnethylundecyl ether of polyethylene-glycol-977-tetrakis (ptoluenesulfonate) N-Lauroyl-N-methy1gluconamine polyethylene-glycol- 264 (Average of 6 ethylene oxide units per molecule). N-Lauroyl-N-methylgluconamine polyethylene-glycol- 264-tetrakis (methanesullonate) N-Lauroyl-N-methylgluconamine polyethylene-glycol- 792-tetrakis methanesulfonate. (Average of 18 ethylene oxide units per molecule). N-Lauroyl-N-methylglueonamine polyethylene-glycol- 792-tetrakis (pyridinium methanesulfonate). N-Lauroyl-N-methylgluconamine polyethylene-glycol- 264-tetrakis(pyridinium methanesulfonate).

Also included among the sensitizers of our invention are the polyfunctional polypropyleneglycol sensitizers and the polyquaternary ammonium salts derived from them as defined by the Formulas I and III.

In general the polyalkyleneglycol derivatives are prepared by reacting the amino alcohols and acids with ethylene oxide (or propylene oxide) in the presence of catalysts, such as Lewis-type acids, tertiary amines, acids or inorganic bases.

However, the addition of polyethylene glycol (or polypropylene glycol) chains to a polycarboxy acid or amide can most conveniently be accomplished by reacting the polycarboxy acid or amide with the desired polyethyleneglycol, such as nonaethyleneglycol, using an acid catalyst. p-Xylene is used to azeotrope off the water formed in the reaction and is collected in a Dean-Stark trap. The preparation of ethylenediamine tetraacetic acidtetr-akis(nonaethyleneglycol ester) was accomplished in this manner. It is understood that this product may contain a monomeric type unit, or may polymerize to give very large molecules containing many ester or amide functions. Epoxides, such as propylene oxide, may be added to acids and also amides under high temperatures and pressures in an autoclave with the usual catalyst, if desired. Monomers and polymers may form in this reaction.

The polyethyleneglycol or polyalkylene oxide derivatives of polycarboxy acids, alcohols, or amides are further converted to the polymethanesulfonates, or hydroxy- Tetrahydroxyethylethylene diamine polyethylene glycol halides, and the resulting po-lyintermediates are quaternized. The polysulfonate esters are formed by reaction of the polyhydroxy compounds with alkyl or aryl sulfonyl chlorides in pyridine; or a polyhydroxy halide may be readily prepared by reaction of the polyglycols with epihalohydrins. The esters and halides readily quaternize with tertiary bases, such as trialkylamines or tertiary nitrogen heterocyclics. Pyridine has been found a superior quaternizing agent for our sensitizing compounds. If desired, the sulfonate or halide anion may be converted to the perchlorate anion with sodium perchlorate.

The molecular weight of'our sensitizing compounds can vary over rather wide ranges because of the different number of alkylene oxide units, such as ethylene oxide or propylene oxide units that they may have per molecule. The alkylene oxide chains on a given molecule of the sensitizers may be of equal or varying lengths. The sensitizing compounds of our invention have molecules with a total of from 6 to 100 alkylene oxide units per molecule, and the total molecular weight of the alkylene oxide units in a molecule may vary from about 264 to about 7200.

Our invention is still further illustrated by a description of the preparations of the representative sensitizing compounds.

SENSITIZER l Ethylenediamine tetraacetic acid, 14.6 g (0.05 mole) was added to 150 ml. of p-xylene, Carbowax 400, a

Carbide and Carbon Co. polyethylene glycol product,

SENSITIZER 2 Forty-one grams (0.10 mole) of tetrahydroxyethylethylenediamine PEG-176 with 2 drops of boron trifiuoride-ether complex (catalyst) was added to a flask equipped with a stirrer, a Dry Ice ace-tone condenser, and gas inlet. The flask was heated to 60 C. on a water bath, and 54 g. (1.2 moles) of ethylene oxide was bubbled into the reaction mixture under the surface of the liquid. After 6 hours, the mixture was heated on the steam bath to remove catalyst and unreacted ethylene oxide leaving a dark yellow oil weighing 95 g. The oil was dissolved in methanol, treated with decolorizing charcoal and diatomaceous filter aid and filtered. After removal of solvent under vacuum, 85 g. of a pale orange colored viscous oil remained which was soluble in water.

SENSITIZER 3 The same process used for making Sensitizer 2 was used but 110.5 g. (2.5 moles) of ethylene oxide was reacted during 4 hours with 46.4 g. (0.20 mole) of tetrahydroxyethylethylenediamine in the presence of the catalyst. After treatment with decolorizing charcoal and filter aid, 132.5 g. of a light-brown viscous syrup was obtained.

SENSITIZER 4 This sensitizer was prepared as was Sensitizer 2 but by the reaction of 46.4 g (0.20 mole) of tetrahydroxyethylethylenediamine with 8 g. (1.8 moles) of ethylene oxide in the presence of three drops of the catalyst over a period of 5 hours. Following treatment with decolorizing charcoal and filter aid, filtration and removal of excess solvent under vacuum, 85.4 g. of Sensitizer 4, a dark viscous oil, was obtained.

6 SENSITIZER 5 Ten grams of tetrahydroxyethylethylenediamine PEG 176 and 9.1 g. of methyl p-toluenesulfona-te were added together with stirring. A mild exothermic reaction raised the temperature to 58 C. The dark red, viscous liquid was heated on the steam bath for an additional two hours to insure complete reaction. The orange colored syrup was then slurried twice with hot benzene to remove unreacted starting material. The oil was dissolved in ethanol, heated with decolorizing charcoal and filtered through a filter bed formed with diatomaceous silica. The solvent was removed on the steam bath under vacuum, giving 11.5 g. of a viscous, water-soluble oil.

SENSITIZER 6 Heptadecylaminopropylamino N,N',N trispolyethyleneglycol-1320 (i.e., Armour and Co.s Ethoduomeen T/), was a dark, viscous syrup as obtained. It was dissolved in acetone, heated with decolorizing charcoal and filtered with diatomaceous silica filter aid through a filter bed, giving a clear, orange syrup. The excess solvent was removed on the steam bath under vacuum, leaving 19.8 g. of an orange syrup which partially solidified upon cooling.

To this product was added 4.5 g. of methyl p-toluenesulfonate and the mixture stirred while a mild exothermic reaction took place. After this had subsided, the mixture was heated on the steam bath for 4 hours. The product was slurried with ether several times, and the ether solution decanted each time. The remaining traces of ether were removed on a steam bath under vacuum, giving a viscous oil.

SENSITIZER 7 1-dimethylamin0-3,6,9-trin1ethyl 3,6,9 triazaundecanol-l, 26 g. (0.10 mole), was heated on the steam bath 1n a flask equipped with a Dry Ice acetone condenser, stirrer, and submerged gas inlet tube. After two and one-half hours of ethylene oxide gas addition, and after removal of the unreacted gas on the steam bath under vacuum, the oil weighed 70.5 g. A weight increase of 53.5 g. indicated that 12.1 .rnoles (PEG525) ethylene oxide had reacted with the amino alcohol.

SENSITIZER 8 Forty grams of the above ethylene oxide addition prod uct containing 12.1 moles of ethylene oxide were heated and reacted under the same conditions as above. After approximately one and one-half hours of addition, 22.5 g. of ethylene oxide by weight were added, giving an oil which now contained 22.2 moles of ethylene oxide (PEG-977) per mole of amino alcohol. For a lightercolored product, the oil was dissolved in methanol, decolorizing charcoal added, and the solution filtered through a diatomaceous silicafilter bed. Concentration of the filtrate under vacuum on the steam bath gave g. of a dark, water-soluble oil.

SENSITIZER 9 The above polyethyleneglycol addition product, 12.4 g. (0.01 mole), and 8.6 g. (0.046 mole) of methyl ptoluenesulfonate were heated together on the steam bath for two hours. The resulting oil was slurried with ether several times to remove traces of unreacted sulfonate ester. The excess solvent was removed on the steam bath under vacuum. Twelve grams of a dark, viscous water-soluble oil was obtained.

SENSITIZER 10 Ethylene oxide 26.5 g. (0.60 mole) was added to 37.7 g. (0.10 mole) of N-lauroyl-N-methylgluconamine in the presence of 3 drops of the catalyst as described in the preceding examples. The ethylene oxide was added over a period of about 4 hours. After purification, there remained 64.2 g. of a viscous orange colored oil soluble in water.

7'- SENSITIZER 11 N-methyl-N-lauroylgluconamine PEG-264, 22.0 g. (0.04 mole), was dissolved in pyridine and chilled to C. Methane sulfonyl chloride, 17.2 g. (0.16 mole), was slowly added through a dropping funnel while the temperature of the reaction mixture was held at 0-10 C. After stirring for two hours, the mixture was allowed to warm up to room temperature. The slurry was acidified with cold hydrochloric acid (1:1) and saturated with sodium chloride. The acidic solution was extracted three times with 200 m1. of warm benzene, and the extract was dried over sodium sulfate. After treatment with decolorizing charcoal, the benzene was removed on a steam bath under vacuum leaving 24 g. of a dark viscous orange colored syrup.

SENSITIZER 12 N-lauroyl-N-methylgluconamine PEG-792 was prepared in the usual manner by the addition of ethylene oxide in the presence of a boron trifluoride catalyst at 85 Twenty-three grams of this addition product was dissolved in 100 ml. of a dry pyridine, chilled to 0", and methanesulfonyl chloride was added with rapid stirring, keeping the temperature below The slurry was stirred at 0 for two hours, then at room temperature for two hours. The slurry was acidified, saturated with sodium chloride and extracted with three 200-ml.. portions of warm benzene. Concentration of the extracts under vacuum on the steam bath gave 16.5 g. of an orange oil.

SEN SITIZER 1 3 The above tetrakis methanesulfonate ester, 16.5 g., 50 ml. of pyridine and 20 ml. of ethanol were refluxed for 1 /2 hours. The excess pyridine was removed under vacuum on the steam bath. The residual oil was dissolved in methanol and precipitated with ether. The ether was decanted and the procedure repeated twice.

The oil was then dissolved in methanol, treated with de-.

colorizing charcoal, the solution was filtered through a diatomaceous silica filter bed, and the solution concentrated. The tetraquaternary salt was isolated as 15.4 g. of a yellow, viscous, water-soluble oil.

SENSITIZER 14 N methyl N lauroylgluconamine PEG264-tetrakis (methanesulfonate), g. and 25 ml. of pyridine were refluxed together for 1 /2 hours. The excess pyridine was removed on the steam bath under vacuum. The oil was dissolved in 10 ml. ethanol and precipitated out with ether. The ether was decanted and the process repeated two more times removing all traces of solvent and excess pyridine under vacuum on the steam bath. Nine grams of an extremely viscous orange colored oil was obtained which Was readily soluble in water.

The compounds of our invention are added to ordinary photographic silver halide emulsions for the purpose of increasing the sensitivity thereof as has been indicated above.

The preparation of photographic silver halide emulsions involves three separate operations:

(1) Emulsification and digestion of silver halide,

(2) The freeing of the emulsion of excess water soluble salts usually by washing with water, and

(3) The second digestion or after-ripening to obtain increased emulsion speed or sensitivity.

(Mees: The Theory of the Photographic Process, 1954.) The sensitizers of our invention can be added to the emulsion before the final digestion or after-ripening or they can be added immediately prior to coating. Our new photographic sensitizers are characterized by not requiring any final digestion or after-ripening in order to obtain optimum sensitivity.

The particular quantity of our sensitizer compound used in a given emulsion will vary depending upon the effects desired, degree of ripening, silver content of the 8 emulsion, etc, The amount used is also dependent upon the particular stage at which the sensitizer is added during the preparation of the emulsion. Generally, from about 50 mg. to about 5 g. of our compounds per mole of silver halide are quite adequate to accomplish the desired sensitization.

Our sensitizers can be added to photographic emulsions using any of the well known techniques in emulsion making. Generally these compounds are soluble enough in water so that the required concentrations are readily obtained. If an auxiliary solvent is needed, solvents such as ethanol, acetone, pyridine, etc., can be used.

It is apparent that the optimum amount of sensitizer compound needed will vary somewhat from emulsion to emulsion and from sensitizer to sensitizer. The optimum amount for a given sensitizer can be determined for any particular emulsion by making a series of tests in which the quantity of our sensitizer is varied over a given range. Exposure of the treated emulsion in a conventional photographic testing apparatus such as an intensity scale sensitometer, followed by development, and image density measurement, will reveal the most advantageous concentration for that sensitizer in that particular emulsion. Such matters are well understood by those skilled in the art.

The photographic emulsions used in practicing our invention are of the developing-out type.

The emulsions can be chemically sensitized by any of the accepted procedures, The emulsions can be digested with naturally active gelatin, or sulfur compounds can be added such as those described in Sheppard U.S. Patent 1,574,944, issued March 2, 1926; Sheppard et al. U.S. Patent 1,623,499, issued April 5, 1927; and Sheppard et al. U.S. Patent 2,410,689, issued November 5, 1946.

The emulsions can also be treated with salts of the noble metals such as ruthenium, rhodium, palladium, iridium, and platinum. Representative compounds are ammonium chloropalladate, potassium chloroplatinate, and sodium chloropalladite, which are used for sensitizing in amounts below that which produces any substantial fog inhibition, as described in Smith and Trivelli U.S. Patent 2,448,060, issued August 31, 1948, and as antifoggants in higher amounts, as described in Trivelli and Smith U.S. Patents 2,566,245, issued August 28, 1951 and 2,566,263, issued August 28, 1951.

The emulsions can also be chemically sensitized with gold salts as described in Waller et al. U.S. Patent 2,399,- 083, issued April 23, 1946, or stabilized with gold salts as described in Damschroder U.S. Patent 2,597,856, issued May 27, 1952, and Yutzy and Leermakers U.S. Patent 2,597,915, issued May 27 1952., Suitable compounds are potassium chloroaurite, potassium aurithiocyanate, potassium chloroaurate, auric trichloride and Z-aurosulobenzothiazole methochloride.

The emulsions can also be chemically sensitized with reducing agents such as stannous salts (Carroll U.S. Patent 2,487,850, issued November 15, 1949), polyamines, such as diethylene triamine (Lowe and Jones U.S. Patent 2,518,698, issued August 15, 1950), polyamines, such as spermine (Lowe and Allen U.S. Patent 2,521,925, issued September 12, 1950), or bis(B-aminoethyl) sulfide and its water-soluble salts (Lowe and Jones U.S. Patent 2,521,926, issued September 12, 1950).

The emulsions can also be optically sensitized with cyanine and merocyanine dyes, such as those described in Brooker US. Patents 1,846,301, issued February 23, 1932; 1,846,302, issued February 23, 1932; and 1,942,- 854, issued January 9, 1934; White U.S. Patent 1,990,507,

issued February 12, 1935; Brooker and White U.S. Patents 2,112,140, issued March 22, 1938; 2,165,338, issued July 11, 1939; 2,493,747, issued January 10, 1950; and 2,739,964, issued March 27, 1956; Brooker and Keyes U.S. Patent 2,493,748, issued January 10, 1950; Sprague U.S. Patents 2,503,776, issued April 11, 1950 and 2,519,- 001, issued August 15, 1950; Heseltine and Brooker U.S.

Patent 2,666,761, issued January 19, 1954; Heseltine U.S. Patent 2,734,900, issued February 14, 1956; Van Lare US. Patent 2,739,149, issued March 20, 1956; and Kodak Limited British Patent 450,958, accepted July 15, 1936.

The emulsions can also be stabilized with the mercury compounds of Allen, Byers and Murray U.S. Patent 2,728,663, issued December 27, 1955; Carroll and Murray U.S. Patent 2,728,664, issued December 27, 1955; and Leubner and Murray U.S. Patent 2,728,665, issued December 27, 1955; the triazoles of Heimbach and Kelly U.S. Patent 2,444,608, issued July 6, 1948; the azaindenes of Heimbach and Kelly U.S. Patents 2,444,605 and 2,444,606, issued July 6, 1948; Heimbach U.S. Patents 2,444,607 issued July 6, 1948, and 2,450,397, issued September 28, 1948; Heimbach and Clark U.S. Patent 2,444,609, issued July 6, 1948; Allen and Reynolds U.S. Patents 2,713,541, issued July 19, 1955; and 2,743,181,

'issued April 24, 1956; Carroll and Beach U.S. Patent 2,716,062, issued August 23, 1955; Allen and Beilfuss U.S. Patent 2,735,769, issued February 21, 1956; Reynolds and Sagal U.S. Patent 2,756,147, issued July 24, 1956; Allen and Sagura US, Patent 2,772,164, issued November 27, 1956; and those disclosed by Birr in Z. wiss. Phot., vol. 47, 1952, pages 2-28; the disulfides of Kodak Belgian Patent 569,317, issued July 31, 1958; the quaternary.benzothiazolium compounds of Brooker and Stand U.S. Patent 2,131,038, issued September 27, 1938 or the polymethylene bis-benzothiazolium salts of Allen and Wilson U.S. Patent 2,694,716, issued November 16, 1954 (e.g., decamethylene-bis-benzothiazolium perchlorate); or the zinc and cadmium salts of Jones U.S. Patent 2,839,405, issued June 17, 1958; and the carboxymethylmercapto compounds of Murray, Reynolds and Van Allan U.S. Patent 2,819,965, issued January 14, 1958.

In the preparation of the silver halide dispersions employed for preparing silver halide emulsions, there may be employed as the dispersing agent for the silver halide in its preparation, gelatin or some other colloidal material such as colloidal albumin, a cellulose derivative, or a synthetic resin, for instance, a polyvinyl compound. Some colloids which may be used are polyvinyl alcohol or a hydrolyzed polyvinyl acetate as described in Lowe U.S. Patent 2,286,215, issued June 16, 1942; a far hydrolyzed cellulose ester such as cellulose acetate hydrolyzed to an acetyl content of 19-26% as described in U.S. Patent 2,327,808 of Lowe and Clark, issued August 24, 1943; a water-soluble ethanolamine cellulose acetate as described in Yutzy U.S. Patent 2,322,085, issued June 15, 1943; a polyacrylamide having a combined acrylamide content of 30-60% and a specific viscosity of 0.25-1.5 on an imidized polyacrylamide of like acrylamide content and viscosity as described in Lowe, Minsk and Kenyon U.S. Patent 2,541,474, issued February 13, 1951; zein as described in Lowe U.S. Patent 2,563,791, issued August 7, 1951; a vinyl alcohol polymer containing urethane carboxylic acid groups of the type described in Unruh and Smith US. Patent 2,768,154, issued October 23, 1956; or containing cyano-acetyl groups such as the vinyl alcohol-vinyl cyanoacetate copolymer as described in Unruh, Smith and Priest U.S. Patent 2,808,331, issued October 1, 1957; or a polymeric material which results from polymerizing a protein or a saturated acylated protein with a monomer having a vinyl group as described in U.S. Patent 2,852,382, of Illingsworth, .Dann and Gates, issued September 16, 1958.

Our emulsions may contain hydrophilic colloid plasticizers, hardeners, coating aids and other addenda as described in Beavers U.S. Serial No. 853,009, now U.S. Patent 3,039,873, filed November 16, 1959.

The sensitizing effects produced by our polyfunctional polyethylene glycols and their polyquaternary salts when they were added to high speed gelatino-silver halide emulsions is illustrated by the following example.

Example 1 A high-speed gelatino-silver iodobromide emulsion panchromatically sensitized with a cyanine dye was coated on a clear cellulose acetate support to yield a silver coverage of 430 mg. per square foot and a gelatin coverage of 1080 mg. per square foot. This material served as a control. Identical coatings of this same emulsion were made which were sensitized by adding our sensitizers in the amounts indicated in Table I. A sample of the control coating and the coatings sensitized with sensitizer No. 1 were given identical sensitometric exposures in an Eastman 1B Sensitometer, given identical 5 minutes development in a developer having the formula:

Water about 125 F. (50 C.) cc 500' p-Methylarninop'henol sulfate g 2.5 Sodium sulfite (desiccated) g 30.0 Hydroquinone g 2.5 Sodium metaborate -8H O g 10.0 Potassium bromide g 0.5

Water to make 1 liter.

then fixed by treating in a fixing bath having the formula:

Sodium thiosulfate g 240.0 Sodium sulfite (desiccated) g 15.0 Acetic acid 28% cc 48.0 Boric acid crystals g 7.8 Potassium alum g 15.0

Water to make 1 liter.

TAB LE I Silver halide emulsion Concentration Fog in sensitized with of sensitizer Relative Gamma density sensitizer number in grams/mole Speed units of silver These data show that high speed photographic emulsions are sensitized by the addition of representative members of our polyfunctional polyethyleneglycol sensitizers and their polyquaternary salts up to relative speeds as high as 3 16 compared to the control speed of 100. The amount of sensitization produced by a given sensitizer depended upon the concentration of the sensitizer used. The optimum concentration of sensitizer can be determined similarly for other of our sensitizers in other silver halide emulsions.

Incorporation of our sensitizers in emulsions intended for color photography, for example, emulsions containing l l color-forming couplers or emulsions to be developed by solutions containing couplers or other color generating materials has indicated their utility therein.

Incorporation of our sensitizers in silver halide emulsions and coated layers designed for use in silver halide diffusion transfer processes of the type described in Rott U.S. Patent 2,532,014; Land U.S. Patents 2,584,029 and 2,543,181; and in Yackel et al. U.S. Patent 3,020,155 gave useful black-and-white trans-fer systems.

Our sensitizers, when added to silver halide emulsions and coated layers designed for dye transfer color processes of the type described in Yutzy U.S. Patent 2,756,142, or in Whitrnore and Mader U.S. patent application Serial No. 734,191, now U.S. Patent 2,954,751, filed May 9, 1958; or in dye developer transfer color processes of the type described in Land U.S. Patents 2,559,643 and 2,698,798; Land and Rogers Belgian Patents 554,933 and 554,934; and in International Polaroid Belgian Patents 554,212 and 554,935, produced color images of improved quality.

The effect of our new sensitizing compounds has been illustrated above with particular reference to ordinary high speed photographic silver bromoiodide emulsions, although it is to be understood that other silver halide emulsions can also be employed to advantage. Our sensitizers can be used in emulsions which are acidic in character or in emulsions which are alkaline. When adding our sensitizers to such emulsions it is generally desirable to adjust the pH of the sensitizing solution so that it will not seriously alter the pH of the emulsion -to be treated.

wherein 2 represents an integer of from 2 to Z represents a member selected from the class consisting of a nitrogen atom and a group; R represents an alkyl group having from 1 to carbon atoms; X is an acid anion; A A and A each represents a member selected from the class consisting of a hydroxypolyalkylene oxyayalkyl group and a hydroXypolyalkylene oxycarbonylalkyl group in which said alkyl group and said alkylene group each has from 2 to 3 carbon atoms, such that when the said alkylene group has 3 carbon atoms, Z represents a group; and B represents a member selected from the class consisting of an alkyl group having from 1 to 20 carbon atoms, an aryl group, an A group, an A group and an A group; those having the formula:

oomormn-on 12 wherein Z is as defined; and n is an integer such that the average value of n is from 8 to 100; and those having the formula:

III 0 H 0 wherein R represents an alkyl group having from 1 to 20 carbon atoms; q and q each represent an integer such that the total of the 4qs and q has an average value of from 6 to 100; Y represents a member selected from the class consisting of a hydroxyl group, a

group and a wherein Z is a member selected from the class consisting of a nitrogen atom and a group; R represents a member selected from the class consisting of an alkyl group having from 1 to 20 carbon atoms; X represents an acid anion; and n n n and in each represent an integer such that the total of n +n +n +n has an average value of from 8 to 100.

3. A high speed photographic gelatino-silver halide emulsion containing a sensitizing amount of a polyfunctional polyalkylene compound selected from those having the formula:

CH3 CH3 R (CHzOH Ohr-H wherein n n n n 11 each represents an integer such that the total of n +n +n +n +n has an average value of from 6 to 100; Y is a member selected from the class consisting of a hydroxyl group,

R R and R each represents a member selected from the class consisting of an alkyl group having from 1 to 4 carbon atoms; and X represents an anionic function.

5. A high speed photographic gelatino-silver halide emulsion containing a sensitizing amount of a sensitizer made by reacting an alkyleneglycol with a compound selected from the class consisting of ethylenediamine tetraacetic acid, alkylaminopropylamine-N,N',N'-trisacetic acid, polyamino alcohols and N-methylgluconamine, said sensitizer containing at least six alkylene glycol units per molecule.

6. A high speed photographic gelatino-silver halide emulsion containing a sensitizing amount of ethylenediamine tetraacetic acid-tetrakis (nonaethyleneglycol ester).

7. A high speed photographic gelatino-silver halide emulsion containing a sensitizing amount of heptadecylaminopropylamine N,N',N tris polyethyleneglycolbis(methyl p-toluenesulfonate) in which the oxyethylene groups have a total molecular weight of 1320 per molecule.

8. A high speed photographic gelatino-silver halide emulsion containing a sensitizing amount of l-trimethylammonium 3,6,9-triaza 3,3,6,6-,9,9-bexamethylundecyl ether of polyethyleneglycol-tetrakis (p-toluenesulfonate) in which the oxyethylene groups have a total molecular weight of 977 per molecule.

9. A high speed photographic gelatino-silver halide emusion containing a sensitizing amount of N-lauroyl- N-methylgluconamine polyethyleneglycol-tetrakis (pyridinium methane-sulfonate) in which the oxyethylene groups have a total molecular weight of 792 per molecule.

10. A high speed photographic gelatino-silver halide emulsion containing a sensitizing amount of N-lauroyl-N- methylgluconamine polyethyleneglycol tetrakis(pyridinium methane-sulfonate) in which the oxyethylene groups have a total molecular weight of 264 per molecule.

11. A process for photographic image development of an exposed high speed photographic gelatino-silver halide emulsion comprising the step of treating said emulsion with an alkaline solution of a silver halide developing agent in the presence of a polyfunctional polyalkylene compound selected from those having the formula: I B\ /A1 Z-(CHzb-Z wherein p represents an integer of from 2 to 10; Z represents a member selected from the class consisting of a nitrogen atom and a group; R represents an alkyl group having from 1 to 14 20 carbon atoms; X is an acid anion; A A and A each represents a member selected from the class consisting of a hydroxypolyalkylene oxyalkyl group and a hydroxypolyalkylene oxcarbonylalkyl group in which said alkl group and said alkylene group each has from 2 to 3 carbon atoms, such that when the said alkylene group has 3 carbon atoms, Z represents a N R X group; and B represents a member selected from the class consisting of an alkyl group having from 1 to 20 carbon atoms, an aryl group, an A group, an A group and an A group; those having the formula:

11 CH3 CH3 Z-CHCHziIi-(CHM CH2 (OCHzC HnM-OH wherein Z is as defined; and n is an integer such that the average value of n is from 8 to and those having the formula:

III CH 0 c alto (0 Hamli wherein R represents an alkyl group having from 1 to 20 carbon atoms; q and q, each represent an integer such that the total of the 4qs and q has an average value of from 6 to 100; Y represents a member selected from the class consisting of a hydroxyl group, a

group and a group; R R and R each represents an alkyl group having from 1 to 4 carbon atoms; and X represents an acid anion.

References Cited by the Examiner UNITED STATES PATENTS 2,423,549 7/ 1947 Blake et al. 96107 2,428,353 10/1947. .Bersworth 260482 2,441,389 5/1948 Blake 96107 2,524,219 10/ 1950 Bersworth 260-482 2,666,700 1/ 1954 Baldsiefen 96-107 3,017,271 1/1962 Piper 96-107 3,039,873 6/1962 Beavers 96108 3,128,183 4/1964 Jones 9610=7 3,150,977 9/1964 Hart 96107 3,158,484 11/1964 Williams et al. 96-107 NORMAN G. TORCHIN, Primary Examiner.

J. T. BROWN, A. E. TANENHOLTZ,

Assistant Examiners.

UNITED STATES PATENT OFFICE V CERTIFICATE OF CORRECTION-- Patent No. 3,253,919 May 31, 1966 Dorothy J. Beavers et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 12, lines 4 to 9, formula III, that portion of the formula reading 0 H should read 0 3 -C-R Signed and sealed this 30th day of December 1969 (SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. J Attesting Officer Commissioner of Patents 

11. A PROCESS FOR PHOTOGRAPHIC IMAGE DEVELOPMENT OF AN EXPOSED HIGH SPEED PHOTOGRAPHIC GELATINO-SILVER HALIDE EMULSION COMPRISING THE STEP OF TREATING SAID EMULSION WITH AN ALKALINE SOLUTION OF A SILVER HALIDE DEVELOPING AGENT IN THE PRESENCE OF A POLYFUNCTIONAL POLYALKYLENE COMPOUND SELECTED FROM THOSE HAVING THE FORMULA: 